A Rainbow Option is used to value mining firms because these firms:

	a.	Have many colourful resources like Rainbows
	b.	Have many decision-making options such as the decision to explore, develop, expand & abandon, etc.
	c.	Face two sources of uncertainties: the price of the reserves in the market and the actual quantity of the reserves
	d.	All the above
	e.	none of the above

The ReOI valuation model has the following advantage(s):

	a.	Financing activities can be ignored in forecasting
	b.	Focuses on core operating income and ignores unusual items
	c.	Requires forecasting NOA in addition to core operating income
	d.	Required return does not have to be adjusted as leverage changes
	e.	all the above